1. Field of the Invention
The present invention is related to a front opening unified pod (FOUP), more particularly to a restraint module being disposed on two platforms adjacent to the recess of inner surface of the door. Thus, the wafer can be disposed within the recess of the door to reduce the size of FOUP, and the wafer restraint component can sustain the wafer to avoid from movement during the wafer transportation.
2. Description of the Prior Art
The semiconductor wafers are transferred to different stations to apply the various processes in the required equipments. A sealed container is provided for automatic transfer to prevent the pollution. FIG. 1 shows the views of wafer container of the conventional prior art. The wafer container is a front opening unified pod (FOUP) which includes a container body 10 and a door 20. The container body 10 is disposed a plurality of slots for placing the plurality of wafers, and an opening 12 is located on the sidewall of the container body 10 for loading or unloading. Further, the door 20 includes an outer surface 21 and an inner surface 22, in which the door 20 is joined the opening 12 of the container body 10 to protect the plurality of wafers within the container body 10. Furthermore, at least one latch component 23 is disposed on the outer surface 21 of the door 20 for opening or closing the wafer container. According to aforementioned, due to the wafer is placed in the container body 10 in horizontal, thus, the FOUP needs a wafer restraint component to avoid from movement during the wafer transportation.
FIG. 2 is a view of a front opening unified pod (FOUP) as described in U.S. Pat. No. 6,736,268. As shown in FIG. 2, the inner surface 22 of the door 20 is disposed with a recess 24 and the recess 24 is extended from the top 221 of the inner surface 22 to the bottom 222, and is located between two locking components 230 (inside of the door 200). The wafer restraint module (not shown in Figure) further includes the recess 24, in which the wafer restraint module consists two wafer restraint components 100, and each wafer restraint component 100 includes a plurality of wafer contact heads 110 to sustain the wafers, so as to prevent the wafer from the moving toward the door opening due to the wafer transportation procedure. However, the wafer restraint module is disposed on the recess 24 of the inner surface 22 of the door 20, and the wafer merely is attached to the inner surface 22 of the door 20 or the wafer is partially settled down within the recess 24. The wafers either sit adjacent to the inner surface 22 of the door 20 or only slightly enter into the recess 24. As resulted, the wafers do not securely and fully settle into the recess 24 in order to effectively shorten the length between the front side and the back side of the FOUP. In addition, the tiny dust particles are generated due to the friction between the wafer restraint module and the wafers can easily accumulate in the recess 24. In the process of cleaning the accumulated dust particles, it is necessary to separate the wafer restraint module from the recess 24 on the inner surface 22 of the door 20. By frequently separation and assembly of the wafer restraint module due to the cleaning process, the wafer restraint module is easily slackened.